In addion to my previous answer.

Oleg Pykhalov <go.wigust@gmail.com> writes:

[…]

>> 'let-alist' is a part of Emacs (that's why it was removed by commit
>> 469c7ce0¹).  Is there a reason to add it?

[…]

> Elpa importer could probably exclude ‘let-alist’ in ‘propagated-inputs’.

Should I remove ‘let-alist’ now?  Maybe we could implement exclude
mechanism for ‘let-alist’ and then remove ‘let-alist’?  ‘let-alist’
shouln't clutter much if it stays in Guix package collection for a time.

Oleg.